SOLUTION: The equation {{{x^2 + y^2 - 2x + 8y + 8 = 0}}} is the equation of a circle. Complete the square to change this equation to standard form. Find the radius and the coordinates of the

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Question 1033689: The equation x%5E2+%2B+y%5E2+-+2x+%2B+8y+%2B+8+=+0 is the equation of a circle. Complete the square to change this equation to standard form. Find the radius and the coordinates of the center of the circle.
Not sure what the first step would be to solve this problem. Any help would be great. Thank you :)
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
x^2 + y^2 - 2x + 8y + 8 = 0
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Rearrange::
x^2 - 2x + y^2 + 8y = -8
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Complete the square on the x-terms and on the y-terms ::
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x^2 - 2x +1 + y^2 + 8y + 16 = -8 + 1 + 16
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(x-1)^2 + (y+4)^2 = 9
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Center:: (1,-4)
radius:: sqrt(9) = 3
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Cheers,
Stan H.
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